Recommended Free Tools
A Linux filesystem that suddenly becomes read-only is often protecting your data after detecting corruption or an underlying I/O problem. The safe fix is not to keep forcing a read-write remount. First identify the affected device, filesystem type, and mount point; read the kernel logs; unmount the filesystem; then run the checker designed for that filesystem while it is offline. For a root filesystem, boot recovery mode or a live environment before repairing it.
Antihost offers Linux VPS plans with full root access, unlimited traffic on a 1 Gbps port and a 14-day free trial.
On ext2, ext3, and ext4, that checker is e2fsck. XFS requires its own recovery and repair procedure. If logs show repeated timeouts, checksum failures, or other media errors, prioritize protecting the files and investigating the storage device instead of repeatedly running repairs.
As an Amazon Associate I earn from qualifying purchases.
Free tools Windows power users keep installed
One-click scans. No signup required.
Why Linux changes a filesystem to read-only
Many ext filesystems are mounted with the errors=remount-ro policy. When the kernel detects a filesystem error, it remounts the filesystem read-only so additional writes do not make the damage worse. You may still be able to list files and copy data, but operations that change metadata or create files fail with messages such as Read-only file system.
A read-only state does not prove that the disk is dead. It can follow a recoverable metadata inconsistency, a journal problem, an interrupted write, or a transient storage failure. It can also be the first visible symptom of failing media, a bad cable, or a controller problem. The kernel log determines which path is appropriate.
#1 Best Overall
- [Ultra-Lightweight Ear Buds Designed for Small Ears] Each earbud weighs only 3.7g and features a compact, ergonomic in-ear design made especially for small ears. Secure, low-profile, and comfortable for workouts, all-day wear or overnight sleeping.The ultra-slim profile sits flush in your ear with no hard edges poking or rubbing, so you can even sleep on your side without discomfort.
- [Immersive Stereo Sound with TOZO OrigX Technology] TOZO OrigX tuning delivers clear vocals, balanced mids, and natural stereo sound for music, podcasts, and videos.
- [Long Battery Life for Daily Use] Get up to 7 hours of playtime on a single charge, with up to 32 hours total using the charging case—ideal for workdays, commuting, and extended listening sessions.
- [Bluetooth 5.3 & Stable Connection] Bluetooth 5.3 provides fast pairing, stable wireless performance, and reduced dropouts as you move around home or office.
- [Deep Bass with Clear Vocals] High-performance drivers produce punchy bass while keeping vocals clean and detailed for everyday listening.
Read-only does not always mean “no writes” on ext4
When an ext4 volume is mounted, the filesystem may replay its journal even if the requested mount mode is read-only. Journal replay changes filesystem metadata. The Linux kernel ext4 documentation specifies that ro,noload prevents journal replay writes. Use that combination when you need a non-replaying read-only inspection, such as copying files or examining a damaged volume from a recovery environment.
Protect data before attempting a repair
If the volume contains important files, stop treating the error as a normal mount problem. Avoid repeated write attempts and do not repeatedly force the filesystem read-write simply to make an application work.
- Stop applications and services that use the affected mount.
- Copy essential files while the volume is still readable, if doing so does not produce more I/O errors.
- Record the device and mount information before changing anything.
- If the logs show repeated I/O errors, timeouts, or hardware-related messages, stop repair experiments and investigate the storage path.
- Have a known backup before a write-capable repair. A filesystem check can correct metadata, but it cannot restore data that the device can no longer read.
A temporary read-write remount only changes the current mount state. It does not correct corruption or a failing device, and new writes can reduce the chance of recovering intact files.
Identify the exact device, filesystem, and mount point
Do not choose a checker from the error message alone. A command such as fsck can dispatch to a filesystem-specific helper, but the helper, options, and safety rules depend on the detected filesystem.
- Run
findmnt -no SOURCE,FSTYPE,OPTIONS /path, replacing/pathwith the affected mount point. The result gives the source device, filesystem type, and active options. - Run
lsblk -fto see block devices, filesystem types, labels, UUIDs, and mount points. This is useful when the error names a device rather than a directory. - Run
mountif you need a complete list of current mounts and options.
| Information | Why it matters | Where to obtain it |
|---|---|---|
| Source device | Identifies the partition or logical volume that must be checked. | findmnt, lsblk -f, or mount |
| Filesystem type | Determines whether to use e2fsck, XFS tooling, or another native checker. |
The FSTYPE field from findmnt or lsblk -f |
| Mount point | Shows which directory is active and whether it can be unmounted. | The mount-point column in lsblk -f or findmnt |
| Mount options | Shows whether the kernel currently has the filesystem read-only and whether special options such as noload are in use. |
The OPTIONS field from findmnt |
Use the actual source returned by these commands. The examples below use /dev/sdb1 only as an example; do not run them against that device unless it is the device you identified.
Rank #2
- 【IP68 Waterproof Multifunctinal Smart Watch】Torjalph fitness activity tracker smart watch is IP68 waterproof technology ,you can wear it when swimming,handwashing,it's rain-proof which means that you perform multiple exercise modes outside without worrying about sweat or rain corroding your fitness smart watch,and this watch equipped with a 230 mAh large capacity battery magnetic charging ,and this sports activity tracker watch can be used 5-7 days If fully charged.
- 【Larger 1.83'' Full Screen Watch & Multi-dial Selection】1.83 inch full HD color touch screen smart watch for men / women provides excellent 240*284 resolution image quality ,This Bluetooth smart watch offers a better touch experience and remarkable immersion and ,more than 200 watch faces for you to choose from App"Da Fit ", you can change the dial style according to your mood to wear keeping the world on your wrist
- 【Accurate Activity Tracker Smart Watch 】sports watch activity tracker uses sweat and dust resistant breathable silicone strap, our Fitness Tracker Smart Watch for Android iOS Phones supports 12 sports modes,walking,running,bicycle,swimming,badminton,basketball,football,rope skipping. This bluetooth calls smart watch for men women is lightweight and stylish, bringing more convenient and relaxing sports experience while also providing more protection.
- 【Your 24 Hour Personal Daily Health Monitor】Fitness watch for women men full touch screen IP67 waterproof bluetooth smartwatch for Android iOS Phones with heart rate blood pressure monitor multifunction Andriod smart watch with steps counter sleep monitor sports fitness watch, monitoring blood oxygen saturation allows you to understand your physical condition in real time to track fitness progress ,to know your health status in time.
- 【More Functions Bluetooth Call Smart Watch】This fitness activity smart watch full screen for iPhone and Android phones includes a bunch of new features including:The bluetooth smart watch can hang up the phone, receive and display WhatsAPP /Text /Facebook /Twitter /Messenger reminder.Support sedentary reminder, alarm clock, stopwatch, timer,weather information,music control, remote camera control compatible with Android 5.0 and above or iOS 9.0 and above smartphones.
Read the kernel evidence before choosing a repair
Filesystem tools report what they find, while the kernel log often explains why the filesystem entered read-only mode. Check both the current boot messages and the kernel journal:
dmesg -T | tail -n 100
journalctl -k -b -p warning..alertLook for messages mentioning filesystem corruption, journal recovery, metadata checksums, block errors, command timeouts, or I/O failures. A single filesystem error with no device errors points toward an offline consistency check. Repeated read failures, transport resets, or timeouts point toward the storage device or its connection. In the latter case, repeatedly forcing a read-write mount can turn a recoverable situation into additional loss.
| Log pattern | What it suggests | Immediate priority |
|---|---|---|
| Metadata, directory, journal, or checksum errors without repeated device failures | Filesystem inconsistency may be repairable offline. | Back up readable data, unmount, and use the native checker. |
| Repeated I/O errors, timeouts, or transport resets | The device, cable, controller, or underlying media may be failing. | Protect data and investigate the storage path before repair attempts. |
| Read-only state after an unclean shutdown, with no continuing errors | Journal recovery or a one-time consistency issue is possible. | Check the filesystem offline and review logs after it is mounted again. |
Choose the procedure by filesystem and mount role
| Detected filesystem | Separate data volume | Root filesystem | Repair tool |
|---|---|---|---|
| ext2, ext3, or ext4 | Stop users, unmount, then run an offline e2fsck check. |
Boot recovery mode or a live environment so the root partition is not mounted, then run e2fsck. |
e2fsck |
| XFS | Follow the XFS-specific unmount and xfs_repair procedure for your distribution. |
Use recovery mode or a live environment and follow the same XFS-specific procedure. | XFS recovery at mount time and XFS repair tooling; not e2fsck |
| Any other filesystem | Use its native checker after unmounting, following that filesystem’s manual. | Use a recovery or live environment if the root filesystem is involved. | The checker native to the detected type |
The target must be unmounted for a normal repair. The fact that a generic fsck command exists does not make every filesystem interchangeable.
Repair an ext2, ext3, or ext4 data volume
1. Stop access and unmount the volume
Stop services and shells that are using the mount. Then unmount it by device or mount point:
sudo umount /dev/sdb1sudo umount /mount/point
Use the device or mount point discovered earlier, not the example blindly. If unmounting fails because the volume is busy, stop the application or service that owns the open files and try a normal unmount again. Do not proceed with a repair while the filesystem remains mounted.
Rank #3
- [Low Noise High Fidelity] New bee guitar cord with 22AWG oxygen-free-copper center conductors provides enhanced signal transfer, the PVC insulation material and the high-density stranded copper double shield provide noise rejection for quiet operation
- [Ideal for Choice] New bee 1/4 straight and right angle metal connectors, ensures a secure connection in any instrument, pedal, or amp jack. L shape great fro on stage guitar stands
- [Wide Compatible] Suitable for mixer, power amplifier, microphone, effector, decoder, equalizer, electoronic organ, electric guitar, electric bass and other electronic equipments. Widely used in the installation of smart home, karaoke speaker, professional stage audio, etc
- [Easy Disassemble] Making incidental repairs quick and easy! Very nice, flexible cable
- [Dont Hesite to Order] 24 hours customer services and professional technology team are standing by
2. Confirm that it is really offline
Run findmnt again for the mount point or inspect lsblk -f. The target should no longer show an active mount. If another path or namespace still has the filesystem mounted, resolve that mount before checking it.
3. Perform a no-change check first
For ext2, ext3, and ext4, use e2fsck. Its -n mode answers “what would be found?” without applying repairs:
sudo e2fsck -n /dev/sdb1Review the device name and the reported filesystem before accepting any repair. A no-change pass is a diagnostic step; it does not make the filesystem consistent.
4. Run the repair only after confirming the target
When you have a backup or have made the best available copy of important data, run the checker against the unmounted ext device:
sudo e2fsck -f /dev/sdb1The e2fsck manual warns that it is generally unsafe to run the program on a mounted filesystem and that results on a mounted filesystem are not valid. The tool may ask how to handle particular inconsistencies. Read each prompt and do not approve changes to a different device by mistake.
Rank #4
- Digital Family Calendar: BSIMB digital calendar wall touch screen puts an end to your chaotic life. Designed for busy families, the digital calendar keeps you organised and in step with your family. Assign different colours and tasks to each family member to make family scheduling easier and more intuitive.
- Easy Setup and Auto-Sync: Plug in, connect to WLAN and auto-syn your electric calendar in minutes. Digital wall calendar compatible with Google calendar, iCloud calendar, Outlook calendar, Cozi calendar and Yahoo calendar. Add events directly on the device or through the ecalendar app. Electronic calendar stays current whether you're at work or traveling—no manual updates needed.
- All-In-One Home Assistant: Smart calendar builds habits and encourage independence with personalised chores. Display daily meal plan to reduce the daily ‘What's for dinner?’ stress. To-do lists keep track of everything you want. Turning chores into valuable achievements with stars and rewards, making life easier and more enjoyable.
- Manage Anytime Anywhere: BSIMB electronic calendar for family stay connected with the powerful ecalendar app. Access and manage your digital wall calendar anytime, anywhere with free features like stars & rewards, photo screensaver, chore charts, meals plans, to-do lists etc. Electronic planner paid features like Magic Import tailor advanced tools for users with special needs.
- Stay in Touch with Loved Ones: Share photos or videos from your phone to electronic wall calendar with app, instantly update your life moment, and keep in touch with your family, especially those who are far away; you can also surprise your smart calendar digital wall by sending him a wish card; it's also great for keeping tech-illiterate elders in touch with the youngsters.
5. Mount again and recheck the evidence
After the check completes, remount the volume through its normal configuration or reboot if that is how the system normally activates it. Confirm the resulting state with:
findmnt -no SOURCE,FSTYPE,OPTIONS /mount/point
dmesg -T | tail -n 100Verify that the expected device and filesystem type are present, note whether the options still include ro, and look for new errors. A clean check followed by fresh I/O errors is not a reason to keep rerunning e2fsck; it is evidence that the underlying storage path still needs attention.
Repair the root filesystem safely
You normally cannot perform a valid repair on the running root filesystem because it is mounted and actively in use. Even if the kernel has remounted it read-only, the root filesystem remains mounted. Running a normal e2fsck pass there can produce invalid results or cause further damage.
- Save essential files while the system can still read them, if possible.
- Reboot into your distribution’s recovery mode, or boot a live environment.
- Identify the root partition again with
lsblk -fandfindmnt. Device names can differ in a live environment. - Ensure the target root partition is not mounted. If the recovery environment mounted it automatically, unmount it before checking.
- Run
e2fsck -nfirst for an ext2, ext3, or ext4 target, then run the repair pass only after confirming the device and protecting available data. - Reboot into the installed system and inspect the mount options and kernel messages again.
If you need to inspect an ext4 volume without allowing journal replay, mount it in the recovery environment with ro,noload at a separate directory:
sudo mount -o ro,noload /dev/sdb1 /mnt/recoveryThis is for non-replaying inspection and data access, not a substitute for an offline consistency repair. The partition must not already be mounted elsewhere, and the mount point must exist.
Use the XFS procedure for XFS
fsck.xfs is not an ext-style generic repair pass. XFS performs recovery at mount time when necessary and uses XFS-specific tooling for repair. Never point e2fsck at an XFS device.
- Confirm
xfsin theFSTYPEresult fromfindmntorlsblk -f. - Stop users and unmount the XFS filesystem. For a root filesystem, use recovery mode or a live environment.
- Follow your distribution’s current
xfs_repairprocedure. Where the installed tool supports a no-change or inspection mode, use it before a write-capable repair. - Run the repair only on the unmounted XFS device and only after confirming the target and protecting readable data.
- Mount or reboot, then review
findmntoutput and kernel logs for continuing errors.
The exact options and recovery requirements differ by XFS version and distribution, so use the manual installed with your system rather than applying ext4 commands by analogy.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Handle other filesystem types
For a filesystem that is neither ext2/3/4 nor XFS, identify its native checker and read its current manual. A generic fsck invocation may dispatch to a helper, but the helper’s options, repair guarantees, and mount-state requirements vary. The safe pattern remains the same: identify the type, stop access, unmount the target, run a diagnostic mode where supported, then perform a repair only with the correct tool.
Why fsck says “the device is mounted”
That message is a safety warning, not an invitation to add a force option. The kernel has the filesystem active, so metadata can change while the checker is reading it. A normal repair run is therefore unsafe and its results cannot be trusted.
- If it is a separate volume, stop the processes using it and unmount the mount point or device.
- If it is the root volume, use recovery mode or a live environment.
- If
findmntstill lists the device after an unmount, check for another mount point or an automatic mount created by the recovery environment. - Do not substitute a different partition because its label or size looks similar; match the source device and UUID shown by
lsblk -f.
When a read-only remount keeps returning
If the filesystem becomes read-only again after a successful check, inspect the new kernel messages before running another check. Persistent metadata errors can mean the repair did not complete, but repeated I/O errors and timeouts more strongly indicate a device or connection problem. In that situation, protect readable data and investigate the storage hardware or transport path. A repair utility cannot correct sectors that the system cannot reliably read.
If there are no continuing filesystem or I/O errors and only a one-time read-only state remains, verify the configured mount options and the result of findmnt. A filesystem can be intentionally configured read-only, and a remount command that changes the current state does not alter the underlying configuration. Correct the configuration only after the filesystem has been checked and the reason for the original remount is understood.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →Quick Recap
Final verification checklist
- The source device, mount point, and filesystem type were identified with current command output.
- Kernel logs were checked for corruption, journal, checksum, timeout, and I/O messages.
- The filesystem was unmounted before a write-capable check.
- The checker matched the filesystem:
e2fsckfor ext2/ext3/ext4, XFS tooling for XFS, and the native checker for other types. - Root repairs were performed from recovery mode or a live environment, not from the running installation.
- Ext4 inspection that must not replay the journal used
ro,noload. - After remounting or rebooting,
findmntand kernel logs were checked again. - Repeated hardware I/O errors were treated as a storage problem rather than as a reason to force more writes.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
